%A WU Chao, WANG Haowen, ZHANG Yuwen, TAN Jianfeng, NI Xianping %T LADRC-based trajectory tracking for unmanned helicopter %0 Journal Article %D 2015 %J Acta Aeronautica et Astronautica Sinica %R 10.7527/S1000-6893.2014.0270 %P 473-483 %V 36 %N 2 %U {https://hkxb.buaa.edu.cn/CN/abstract/article_15722.shtml} %8 2015-02-15 %X

Trajectory tracking control system is used for decoupling the control unmanned helicopter, which is a nonlinear system with multi-input/multi-output and strong coupling effects. In order to avoid the dependence on accuracy of unmanned helicopter physical parameters measurement and identification and to reduce external disturbance impact, a multi-loop controller based on linear active disturbance rejection control (LADRC) is proposed. At first, the flight dynamics model is built for unmanned helicopter X-Cell. The atmospheric disturbance model, which contains wind shear, turbulence and gust model, is also set up for accurate simulation of real flight environment. Secondly, X-Cell is trimmed for verifying the accuracy of dynamic model and trim algorithm. A set of calculation values is selected as the initial state and input of the subsequent simulation. Then attitude, velocity and position control loop are built based on the first-order and second-order LADRC controllers which are selected according to system order. Combined with the time-scale separation principle, the whole trajectory control system is constructed from inner loop to outer loop. After that, the stability of the system is analyzed. The characteristic roots show that the whole system becomes stable with the trajectory controller. Finally, flight simulation experiments under various disturbance conditions are performed. The results show that the established control system can achieve a good climbing figure-eight trajectory tracking. Compared with controller based on proportion integration differentiation(PID), the controller based on LADRC has better robustness and capability of anti-disturbance.